There is nothing original about Pentax SDM and Pentax don't make the ultrasonic motors either, it's like saying the sensor in the D7000 is made by Nikon while we all know it's from Sony, also Pentax won't officially say they use Sony sensor in the K5.
It's very likely that in the DA* lenses there are different ultrasonic motors and that the same motors are use by other brands as well, they are off the self products.
Same with the processor, the Prime II is just a Fujitsu Milbeaut that also Nikon use....
It's the same with Apple A4 processor in the iPhone 4, the chip is for the most part designed and fully manufactured by Samsung...
Could very well be that in one of the lenses their Ultrasonic Engine is used
http://www.fukoku-rubber.co.jp/english/product/ultrasonic_motor.html
Canon, Fukoku, Asmo, SII, Canon Precision, Shinsei, Kyocera, Olympus and Mitsuba or the ones in Japan making these motors.